For timing purposes, is it possible to control the number of threads / cores when I have compiled R to use the BLAS in the Accelerate framework (by building R using ./configure --with-blas="-framework Accelerate" --with-lapack ) ? (The alternative is of course to build R using the supplied single-threaded BLAS) Best, Kasper
disabling threads when using Accelerate BLAS
4 messages · Kasper Daniel Hansen, Brian Ripley, samitpaulin
On 08/09/2018 22:01, Kasper Daniel Hansen wrote:
For timing purposes, is it possible to control the number of threads / cores when I have compiled R to use the BLAS in the Accelerate framework (by building R using ./configure --with-blas="-framework Accelerate" --with-lapack ) ? (The alternative is of course to build R using the supplied single-threaded BLAS)
This is a question about Accelerate not R. But the R-admin manual does say 'In recent versions of macOS, threading in Accelerate is controlled by ?Grand Central Dispatch? and is said not to need user control.' It has quite a few other caveats about Accelerate, not least that it uses an LAPACK which is missing many bug fixes, some serious.
Brian D. Ripley, ripley at stats.ox.ac.uk Emeritus Professor of Applied Statistics, University of Oxford
Thanks for the extremely helpful pointers on this. Clearly I need to remove --with-lapack in my configure step. On Sun, Sep 9, 2018 at 4:12 AM Prof Brian Ripley <ripley at stats.ox.ac.uk> wrote:
On 08/09/2018 22:01, Kasper Daniel Hansen wrote:
For timing purposes, is it possible to control the number of threads / cores when I have compiled R to use the BLAS in the Accelerate framework (by building R using ./configure --with-blas="-framework Accelerate" --with-lapack ) ? (The alternative is of course to build R using the supplied single-threaded BLAS)
This is a question about Accelerate not R. But the R-admin manual does say 'In recent versions of macOS, threading in Accelerate is controlled by ?Grand Central Dispatch? and is said not to need user control.' It has quite a few other caveats about Accelerate, not least that it uses an LAPACK which is missing many bug fixes, some serious. -- Brian D. Ripley, ripley at stats.ox.ac.uk Emeritus Professor of Applied Statistics, University of Oxford
18 days later
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